经颅磁声电刺激对大鼠工作记忆局部场电位gamma节律的影响

Effects of Transcranial Magneto-Acoustic-Electrical Stimulation on Gamma Rhythm of Local Field Potentials during Working Memory Task of Rats

经颅磁声电刺激(TMAES)是一种新型无创的神经调控技术,利用超声与静磁场相互耦合产生感应电场,调节相应脑区的神经节律振荡活动,从而影响大脑学习、记忆等认知功能。为探究经颅磁声电刺激对大鼠工作记忆(WM)行为学实验中gamma节律神经振荡活动的影响,将20只健康成年Wistar大鼠随机分为对照组和刺激组,刺激组大鼠接受0.05~0.15 T、1.33~13.33 W/cm^(2)的经颅磁声电刺激,持续10 d,对照组不接受刺激;采集T型迷宫工作记忆任务中大鼠前额叶皮层(PFC)的局部场电位信号(LFPs),对比分析两组间的行为学差异、LFPs的时频分布和互信息相关性。结果显示,刺激组大鼠执行工作记忆任务达到正确率80%以上所需时间为(7.57±0.99)d,明显少于对照组(10.65±2.32)d(P<0.05);在经过选择点位置前后,2.66~13.33 W/cm^(2)组、0.10~0.15 T组大鼠LFPs信号gamma频段的能量密度明显高于对照组的相应值(P<0.05),6.65~13.33 W/cm^(2)组、0.10~0.15 T组大鼠gamma频段12通道信号间的相关性明显强于对照组的相应值(P<0.05)。研究结果表明,经颅磁声电刺激能够增强大鼠工作记忆中前额叶皮层神经元集群gamma节律振荡活动,为进一步探索经颅磁声电刺激调节大脑记忆功能的作用机制奠定基础。

Transcranial magneto-acoustic-electrical stimulation(TMAES)is a new non-invasive neural regulation technique,which uses ultrasound and static magnetic field to generate an induction electric field to regulate the oscillating activities of the corresponding brain regions,thus affecting cognitive functions such as learning and memory.The purpose of this study was to investigate the effects of TMAES on the oscillations of gamma rhythmic nerve during the working memory(WM)behavior experiment in rats.Twenty healthy adult Wistar rats were divided into control group and stimulation group.The stimulation group received TMAES of 0.05~0.15 T and 1.33~13.33 W/cm;for 10 days,while the control group didn’t accept any stimulations.The local field potentials(LFPs)in the prefrontal cortex(PFC)of the two groups of rats were recorded during the T-maze working memory task,and the behavioral differences,time-frequency distribution of the local field potential and correlation of mutual information between the two groups of rats were compared and analyzed.The experimental results showed that the time required for the rats in the stimulation group to perform the working memory task to achieve the correct rate above 80%was(7.57±0.99)d,which was significantly less than(10.65±2.32)d in the control group(P<0.05).Before and after passing through the behavioral selection position,the energy density of gamma band of local field potential signal in 2.66~13.33 W/cm;group and0.10~0.15 T group was significantly higher than that in the control group(P<0.05).The correlation between the 12 channel signals of the gamma band of rats in 6.65~13.33 W/cm;group and 0.10~0.15 T group was significantly stronger than that in the control group(P<0.05).The results indicated that the transcranial magneto-acoustic-electrical stimulation could enhance the rhythmic oscillating activity of prefrontal cortex neurons in working memory of rats,which lays a foundation for exploring the mechanism of TMAES regulating brain memory function.